An apparatus for processing a sample or reagent in the sense of the present invention comprises a pipetting device. Such pipetting devices are used for transferring a sample or reagent from a first vessel to a second vessel by means of an aspirating and dispensing operation. Modern apparatus for processing samples of this kind are largely fully automatic in operation and only the samples and/or reagents stored in the vessels have to be inserted into the apparatus and the desired process such as aliquoting or an analysis has to be entered.
The present invention is intended for apparatus such as analytical instruments which operate with liquid samples or reagents which are contained in first vessels. Usually, the samples or reagents stored in the first vessels are withdrawn from the first vessels by pipette probes of a pipettor at the analytical position. Particularly, the pipetting probe of the pipettor is fastened to a moveable arm, dips from above through the open first vessel and an appropriate amount of sample or reagent is sucked in and transferred in the pipette probe, which is also known as transfer needle, to a second vessel. Usually, the first vessels are arranged on a rack in a predetermined pattern. These are handled by multiple automatic pipetting channels of the pipetting device. At the same time, it is required to process either all or just some of the pipetting channels. Multiple pipetting channels working in parallel are disclosed for example in EP 2 410 342 A2.
Using the above described pipetting devices with an analytical instrument provides advantages concerning the parallel handling. Nevertheless, there are still some drawbacks. Particularly, such automatic pipetting devices have an individual control over each pipetting channel which requires much space and many actuators for all individual control mechanisms. Thus, the more pipetting channels are handled by the automatic pipetting device, the more the costs for the pipetting process increase. Further, the space required for the control mechanisms increases due to the increasing number of actuators.
It is therefore an objective of the present invention to provide a pipetting device for an apparatus for processing a sample or reagent, an apparatus for processing a sample or reagent, and a method for pipetting a sample or reagent using such a pipetting device which are improved regarding complexity in the construction and the handling of the samples or reagents. Particularly, there is a desire to provide a pipetting device and an apparatus for processing a sample or reagent with which several pipetting channels may be controlled by using less actuators and space as possibly thereby reducing the costs of the automatic pipetting device.